Single phase grating x-ray microscopic imaging system based on two-stage amplification

Abstract

The application discloses a single-phase grating X-ray microscopic imaging system based on two-stage amplification, which comprises a geometric amplification system, an optical amplification system and a detector; the geometric amplification system comprises an X-ray light tube, a plurality of capillary tubes, a phase grating and a scintillator; the optical amplification system amplifies a fluorescent signal to obtain a fluorescent amplified signal, separates the fluorescent amplified signal from a first modulation signal, and obtains the fluorescent amplified signal; and the detector receives the fluorescent amplified signal. The application uses the plurality of capillary tubes to focus X-rays to realize geometric amplification, uses a scintillator coupled lens imaging system to realize optical amplification, uses two-stage amplification to realize high-resolution microscopic imaging, realizes high resolution without relying on a high-coherence X-ray beam, uses the light source segmentation characteristics of the plurality of capillary tubes, uses only one phase grating to modulate an object, acquires multi-modal information, and does not need two absorption gratings required by a traditional X-ray phase contrast system, thereby greatly improving system light flux and imaging contrast.

Description

Technical Field

[0001] This invention relates to the field of X-ray technology, and more particularly to a single-phase grating X-ray microscopy imaging system based on two-stage amplification. Background Technology

[0002] Compared with X-ray imaging technology, X-ray phase contrast imaging has the following advantages: because weakly absorbing materials have small absorption attenuation of X-rays, but the phase change amplitude of X-rays is large when they pass through, X-ray phase contrast imaging can observe materials that are difficult to observe with X-ray imaging technology, and has a wider range of applications; X-ray phase contrast imaging has higher sensitivity and higher resolution, and can form clearer images; X-ray phase contrast imaging requires a lower radiation source dose and is relatively safer.

[0003] X-ray phase-contrast imaging methods mainly include crystal interferometry, diffraction enhancement, coaxial phase-contrast imaging, and grating phase-contrast imaging. Due to the influence of the light source and the crystal, crystal interferometry and diffraction enhancement have relatively poor applicability, while coaxial phase-contrast imaging and grating phase-contrast imaging have relatively better applicability. Among them, grating phase-contrast imaging has the advantages of good light source compatibility and a large imaging field of view, and is the mainstream research direction. X-ray phase-contrast imaging equipment based on the grating method mainly consists of an X-ray tube, grating, detector, motion device, automatic control system, and image processing system.

[0004] X-ray phase-contrast imaging shows great potential in biomedical imaging because, compared to traditional transmission X-ray imaging, grating-based X-ray phase-contrast imaging offers higher sensitivity and is a promising technique. Furthermore, the use of gratings removes the coherence limitation of the light source in X-ray phase-contrast imaging. Grating-based X-ray phase-contrast imaging can obtain multimodal information on object absorption, phase, and dark field, showing significant application prospects in medical detection, bioimaging, and materials analysis. However, the absorption of X-rays by grating devices reduces the radiation received by the object; the transmittance of absorption gratings is around 30%-40%, which places higher demands on the power of the light source and the corresponding heat dissipation capabilities. Therefore, techniques using only phase gratings are continuously being developed.

[0005] As imaging resolution continues to improve, the requirements for X-ray microscopy are also increasing, demanding higher light throughput and image quality. X-rays have extremely short wavelengths, with a diffraction limit on the picometer scale, much higher than the upper limit of traditional microscopy methods. X-ray microscopy combined with phase-contrast information can reveal more details, making significant strides in fields such as medical diagnosis and bioanalysis.

[0006] However, in existing technologies, multiple gratings are used for processing when performing geometrically magnified phase-contrast imaging. On the one hand, the requirements for the light source are relatively high, and on the other hand, due to the large number of structures involved, the overall data processing method is quite complicated. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a single-phase grating X-ray microscopy imaging method and apparatus based on two-stage amplification.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] A single-phase grating X-ray microscopy imaging system based on two-stage amplification includes a geometric magnification system, an optical magnification system, and a detector;

[0010] The geometric amplification system includes an X-ray tube, multiple capillaries, a phase grating, and a scintillator;

[0011] The inlet end of the multi-capillary tube is provided with an X-ray tube. The multi-capillary tube is used to converge the X-ray beam emitted by the X-ray tube and decompose it into discrete point light sources that meet the spatial coherence condition and are incoherent with each discrete point light source. The discrete point light sources pass through the phase grating.

[0012] The phase grating generates a diffraction self-imaging effect on the discrete point light source, forming a contrast-enhanced modulation signal, which is used to illuminate the sample under test.

[0013] The scintillator converts the first modulation signal after passing through the sample into a fluorescence signal in the visible light band;

[0014] The optical amplification system amplifies the fluorescence signal to obtain a fluorescence amplified signal, and separates the fluorescence amplified signal from the first modulation signal to obtain the fluorescence amplified signal;

[0015] The detector receives the amplified fluorescence signal;

[0016] The optical amplification system amplifies fluorescence signals in the visible light band, and the amplification factor of the geometric amplification system is 1 to 40. The wavelength range corresponding to the visible light band is 400 nm to 700 nm, so that the limit resolution of the image of the sample under test can reach 20 nm.

[0017] As one possible implementation method, the magnification imaging formula of the geometric magnification system is described as follows:

[0018]

[0019] Where l1 and l2 represent the distance from the focal point of the multi-capillary tube to the sample under test and the distance from the sample under test to the scintillator, respectively, θ represents the divergence angle of the multi-capillary tube, and y1 represents the size of the resolvable feature of the image of the sample under test.

[0020] As one possible implementation, the formula for the Talbot distance between the discrete point source and the phase grating in the diffraction self-imaging effect is as follows:

[0021]

[0022] Where λ represents the incident light wavelength, and p1 represents the grating period, which determines the distance from the phase grating to the scintillator.

[0023] As one possible implementation, the optical magnification system includes an objective lens module, a reflection module, and a field lens module;

[0024] The objective lens module collects and amplifies the fluorescence signal generated by the scintillator to obtain a fluorescence amplification signal. The objective lens module is a 20x objective lens with a numerical aperture of 0.55 and a diffraction limit of 887nm to 1552nm.

[0025] The reflection module is equipped with a visible light band reflection film to separate the fluorescence amplification signal and the first modulation signal to obtain a single fluorescence amplification signal;

[0026] The field lens module is used to reduce the light-transmitting aperture of the image and to compensate for the optical aberrations generated by the objective lens module.

[0027] The formula for optical magnification obtained through the objective lens module and the field lens module is as follows:

[0028]

[0029] Where, d WD f1 represents the working distance of the objective lens module, f2 represents the equivalent focal length of the objective lens module and the field lens module, respectively, and d represents the distance between the objective lens module and the field lens module.

[0030] As one possible implementation, it also includes an information processing device connected to the detector;

[0031] The information processing device receives and analyzes at least the following information:

[0032] The image includes an exposure image of the sample to be tested and a background exposure image without the sample to be tested. The exposure image containing the sample to be tested is obtained by superimposing the signal generated by the discrete point light source directly illuminating the sample to be tested and the image of the sample to be tested is obtained by superimposing the first modulation signal generated by the modulation signal illuminating the sample to be tested. The background exposure image is obtained under the same exposure conditions without the sample to be tested.

[0033] As one possible implementation method, the following steps are also included:

[0034] At least three exposure images of the sample to be tested must be acquired;

[0035] The corresponding pixels of the three exposure images of the sample to be tested are combined with the modulation signal generated by the phase grating to obtain multimodal information. The multimodal information is then decomposed to obtain absorption information, phase information and dark field information.

[0036] Based on the three types of information obtained from multimodal information analysis and the principle of minimizing errors, the random errors caused by mechanical motors and the drift errors caused by grating jitter during the phase grating stepping process are optimized, thereby determining the optimal state of the phase grating.

[0037] As one possible implementation method, the following steps are also included:

[0038] Flat-field correction is performed by centroid positioning and Gaussian beam fitting to adjust the position of the multi-capillary tubes, thereby adjusting the distribution of discrete point light sources.

[0039] As one possible implementation method, the following steps are also included:

[0040] Acquire an image of the sample under test containing the first modulation signal and a background exposure image without the sample under test;

[0041] The characteristic values ​​of the first modulation signal are calculated by using the phase stepping method to obtain the three contrast information of absorption, phase and dark field after separation, between the sample image to be tested and the background exposure image. The characteristic values ​​include amplitude, phase and contrast.

[0042] As one possible implementation, the phase grating is a hexagonal grid grating;

[0043] The modulation intensity of the hexagonal grid grating and the discrete point light source formed by each single tube in the multi-capillary tube corresponds to each other, so that the formed image is a diffractive conjugate image; the spacing between the hexagonal grid grating and the multi-capillary tube satisfies incoherent superposition enhancement.

[0044] This invention, by adopting the above technical solutions, has significant technical effects:

[0045] This invention uses multi-capillary focusing X-rays to achieve geometric magnification and a scintillator-coupled lens imaging system to achieve optical magnification. The two-stage magnification achieves high-resolution microscopic imaging, achieving high resolution without relying on a highly coherent X-ray source (synchrotron radiation source, liquid metal target source) or Fresnel zone plate. In addition, by utilizing the light source segmentation characteristics of multi-capillary focusing, only one phase grating is needed to modulate the object and acquire multimodal information, eliminating the need for two absorption gratings required by traditional X-ray phase contrast systems, thus greatly improving the system's light throughput and imaging contrast. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the system of the present invention;

[0048] Figure 2 This is a schematic diagram of a geometrically magnified system;

[0049] Figure 3 This is a schematic diagram of an optical magnification system;

[0050] Figure 4 This is a schematic diagram illustrating three types of contrast information;

[0051] Figure 5 This is a schematic diagram of the overall system according to a specific embodiment of the present invention. Detailed Implementation

[0052] The present invention will be further described in detail below with reference to the embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0053] A single-phase grating X-ray microscopy imaging system based on two-stage amplification, such as Figure 1As shown, the system includes a geometric amplification system, an optical amplification system 10, and a detector 9. The geometric amplification system includes an X-ray tube 1, a multi-capillary tube 2, a phase grating 3, and a scintillator 5. The X-ray tube 1 is installed at the inlet end of the multi-capillary tube. The multi-capillary tube 2 is used to converge the X-ray beam emitted by the X-ray tube 1 and decompose it into discrete point sources that satisfy the spatial coherence condition. Each discrete point source is incoherent with each other. The discrete point sources directly irradiate the sample 4 under test and / or pass through the phase grating 3. The phase grating 3 generates a diffraction self-imaging effect on the discrete point sources, forming a contrast-enhanced modulation signal. The modulation signal is used to irradiate the sample 4 under test. The scintillator 5 converts the first modulation signal after passing through the sample 4 under test into a fluorescence signal in the visible light band. The optical amplification system 10 amplifies the fluorescence signal to obtain a fluorescence amplified signal and separates the fluorescence amplified signal from the first modulation signal to obtain a fluorescence amplified signal. The detector 9 receives the fluorescence amplified signal.

[0054] This invention utilizes multi-capillary focusing of an X-ray beam to achieve geometric magnification, and an optical magnification system to achieve optical magnification. This two-stage magnification enables high-resolution microscopic imaging with nanometer-level precision. Furthermore, a phase grating performs self-imaging on each point source decomposed by the multi-capillary system, acquiring multimodal information of the object through phase-contrast imaging. Simultaneously, the microscopic system structure eliminates the need for a resolving grating, and the overall system does not require an absorption grating or Fresnel zone plate, significantly improving system luminous flux and imaging contrast. In the geometric magnification system, multi-capillary focusing of the X-ray beam achieves geometric magnification, such as... Figure 2 As shown, this simultaneously focuses the large focal spot generated by the X-ray tube into a small focal spot, improving the spatial coherence of the light source. Geometric magnification imaging can be described by the following formula:

[0055]

[0056] Where l1 and l2 are the distances from the focal point of the multi-capillary tube to the sample under test and the distance from the sample under test to the scintillator, respectively; θ is the divergence angle of the multi-capillary tube; and y1 represents the size of the resolvable feature in the image of the sample under test.

[0057] The optical magnification system includes an objective lens module, a reflection module, and a field lens module. The objective lens module collects and amplifies the fluorescence signal generated by the scintillator to obtain an amplified fluorescence signal. The reflection module is equipped with a visible light band reflective film to separate the amplified fluorescence signal from the first modulation signal, resulting in a single amplified fluorescence signal. The field lens module is used to reduce the aperture of the imaging system. The optical magnification formula obtained through the objective lens module and the field lens module is as follows:

[0058]

[0059] Where, d WDThe working distance of the objective lens module is given by f1 and f2, which are the equivalent focal lengths of the objective lens module and the field lens module, respectively, and d is the distance between the objective lens module and the field lens module. In a specific embodiment, the objective lens module, the reflection module, and the field lens module can be the objective lens, the radiation lens, and the field lens, respectively. The field lens module is used to correct optical aberrations for the high-magnification objective lens module. The scintillator in this invention can be a single scintillator or a multi-scintillator. For a single scintillator, it can be considered as single-wavelength imaging, and no chromatic aberration correction is required; while for multi-spectral imaging with multiple scintillators, chromatic aberration optimization is required for specific wavelengths. The objective lens module uses a microscope objective lens, which is usually a plan objective lens, and the field lens module has already been corrected. Large-aperture imaging requires focused optical design optimization for spherical aberration and coma to obtain the best imaging quality. In order to reduce the impurities in the fluorescence amplification signal, a reflector is used in the optical amplification system to separate the fluorescence amplification signal and the first modulation signal, reducing the influence of background noise. At the same time, the deflection of the optical path compresses the overall system volume, which helps to realize a compact microscope system.

[0060] On the one hand, the optical magnification system can alleviate the magnification requirements of geometric magnification. This design can reduce aberrations, thereby increasing the divergence angle of the multi-capillary to reduce the overall length of the imaging system. On the other hand, the geometric magnification system requires a large area and a small period for the resolving grating in traditional phase-contrast imaging. However, in this invention, the addition of the optical magnification system allows the small-period modulation signal to be directly captured by the detector, requiring only a small-area phase grating for modulation. This greatly reduces the requirements for manufacturing and improves the practicality of phase-contrast imaging.

[0061] When an X-ray beam illuminates a periodically absorbing structure (such as an absorption grating or a phase grating), a self-image of the object is generated at a specific location behind it. This self-image effect is essentially a result of Fresnel diffraction (near-field diffraction). The location where this self-image occurs, i.e., the Talbot distance, can be described by the following formula:

[0062]

[0063] Where λ is the incident light wavelength and p1 is the grating period. Since the wavelength of X-rays is extremely short, much shorter than the grating period, a Taylor expansion of the above formula, ignoring higher-order terms, yields the following rewrite of the Talbot distance formula:

[0064]

[0065] Where λ is the incident light wavelength and p1 is the grating period, i.e., the distance from the phase grating to the detector is determined. The Talber distance between the light source and the phase grating is calculated using the above formula, i.e., the distance from the phase grating to the scintillator is determined.

[0066] Because grating-based self-imaging methods require high coherence of the light source, traditional methods can only operate with synchrotron radiation sources or micro-focus X-ray sources. However, these sources are bulky, expensive, and have limited availability. Therefore, large-focus X-ray beams can be converted into partially coherent sources to meet spatial coherence requirements. Multiple capillaries are placed after the X-ray beam to divide it into discrete point sources. These discrete point sources are spatially incoherent, but each point source internally satisfies spatial coherence conditions. By controlling the spacing and period of the subsequent phase grating and capillaries, the self-images of the decomposed discrete point sources are superimposed, improving imaging contrast and resulting in a contrast-enhanced modulation signal.

[0067] The contrast-enhanced modulation signal, after passing through the sample under test, produces an image containing various contrast information, such as... Figure 4 As shown, absorption contrast originates from X-ray beam intensity attenuation, differential phase contrast originates from X-ray refraction, and dark field contrast originates from small-angle scattering information. Traditional X-ray beam transmission imaging only considers absorption contrast. In practice, several contrast information types are fused together, so it is necessary to separate the information through methods such as phase grating modulation to achieve high-sensitivity, multi-information imaging.

[0068] The system also includes an information processing unit connected to the detector; the information processing unit receives and analyzes at least the following information:

[0069] The image includes an exposure image of the sample to be tested and a background exposure image without the sample to be tested. The exposure image containing the sample to be tested is obtained by superimposing the signal generated by the discrete point light source directly illuminating the sample to be tested and the image of the sample to be tested is obtained by superimposing the first modulation signal generated by the modulation signal illuminating the sample to be tested. The background exposure image is obtained under the same exposure conditions without the sample to be tested.

[0070] First, an exposure image containing the sample to be tested and a background exposure image excluding the sample to be tested are acquired. The corresponding pixels of the exposure image of the sample to be tested are combined with the modulation signal generated by the phase grating to obtain multimodal information. The multimodal information is decomposed to obtain absorption information, phase information, and dark field information. Based on the various information obtained from the multimodal information analysis and the principle of minimizing errors, the errors generated during the stepping process are optimized to improve image quality. The exposure image of the sample to be tested and the background exposure image are combined to eliminate the influence of grating defects, light field distribution, etc.

[0071] It also uses frequency domain methods to decompose the multimodal information of the absorption, phase, and dark field of the sample under test, so that only two exposures are needed, namely the test image of the sample under test and the background image without the sample under test, and only one exposure is needed for the sample under test, which greatly reduces the exposure dose.

[0072] In one specific embodiment, a hexagonal grid grating is used as a self-imaging phase grating, corresponding to the discrete point light source formed by each individual capillary tube. Compared with the traditional two-dimensional checkerboard grating, it has high phase sensitivity in three directions and can obtain higher imaging quality.

[0073] In addition, Gaussian beam fitting of the light source spot is used to eliminate the problem of uneven distribution in multi-capillary imaging. During the process of converting a cone-shaped X-ray beam into a quasi-parallel beam, the reflection efficiency of different beam segments varies, resulting in an uneven distribution of light spot intensity, which is approximately Gaussian. Flat-field correction is performed through centroid localization and Gaussian beam fitting, which largely eliminates the unevenness of light intensity distribution in the image and enhances edge information.

[0074] In subsequent use, neural network algorithms will be used to learn specific features and obtain the system imaging transformation relationship, which can be used to image tissue structures such as the lungs and breasts, thereby obtaining image quality no less than that obtained by traditional stepping methods on the basis of a single exposure.

[0075] In summary, based on the above-described structure of the present invention, the imaging method of the present invention is as follows:

[0076] The X-ray beam emitted by the X-ray tube is focused by multiple capillaries to geometrically magnify and image the sample under test. Optical magnification is further achieved through a scintillator-coupled lens detection system. This two-stage magnification enables nanometer-level precision microscopic imaging. Simultaneously, the X-ray beam is decomposed by the capillaries into numerous discrete point sources that internally satisfy spatial coherence conditions. Under these partial coherence conditions, a phase grating generates a diffraction self-imaging effect on these discrete point sources, resulting in superposition and a contrast-enhanced modulation signal. This modulation signal passes through the sample under test to obtain an image of the sample. This image includes phase modulation information. Due to the absorption, attenuation, refraction, and small-angle scattering of the modulation signal by the sample under test, changes occur in the amplitude, phase, and contrast of the modulation signal. A background exposure image excluding the sample under test is then exposed. The changes in both the sample image and the background exposure image are calculated using a phase-stepping method to obtain the absorption, phase, and dark-field contrast information of the separated sample.

[0077] The imaging principle is as follows:

[0078] After the modulated signal passes through the sample under test, its intensity attenuates, and it is deflected and scattered at small angles due to the complex refractive index of the sample. The signal contains not only attenuation information within the sample but also its complex refractive index and scattering information. Therefore, by inversely calculating the projection data, the spatial position of the sample and its material information can be obtained, including material information such as the X-ray attenuation coefficient, complex refractive index, and scattering coefficient, which is more beneficial for feature extraction and material analysis.

[0079] The workflow is as follows:

[0080] A rotating stage is installed on the sample to be tested, and the center of the imaging optical path passes through and is orthogonal to the rotation axis of the rotating stage. Multi-angle phase contrast imaging is obtained by rotating the rotating stage of the sample to be tested. The absorption contrast and dark field contrast information of the sample to be tested are directly back-projected. The phase contrast information is first subjected to Hilbert transformation and then back-projected. The spatial positions of the tomographic scan images of the three contrast information are corresponding, but the material information is different, which allows for more detailed region segmentation and material analysis.

[0081] For more details, see Appendix Figure 5 As shown, attached Figure 5 In one specific embodiment, it includes an X-ray tube 1, a multi-capillary tube 2, a phase grating 3, a sample to be tested 4, a scintillator 5, a microscope objective 6, a mirror 7, a field lens 8, and a detector 9.

[0082] The X-ray beam emitted by X-ray tube 1 is focused by multi-capillary tube 2 to image and geometrically magnify the sample 4 under test, resulting in a geometrically magnified image of the sample 4. Multi-capillary tube 2 decomposes the X-ray beam into many discrete point sources that internally satisfy the spatial coherence condition. Each discrete point source is incoherent with each other. A phase grating 3 generates a diffraction self-imaging effect on these discrete point sources, achieving incoherent superposition and enhanced imaging contrast, thus obtaining a modulated signal. The period and spacing between multi-capillary tube 2 and phase grating 3 must satisfy the aforementioned partial coherence condition. The modulated signals obtained from multi-capillary tube 2 and phase grating 3 are superimposed on the sample 4 under test, resulting in an image of the sample containing the first modulated signal.

[0083] Scintillator 5, microscope objective 6, reflector 7, field lens 8, and detector 9 sequentially optically amplify the first modulation signal to achieve nanoscale microscopic imaging. Scintillator 5 converts the first modulation signal after passing through the sample into a visible light fluorescence signal, which is then imaged onto detector 9 via microscope objective 6, reflector 7, and field lens 8. Data is acquired, analyzed, and processed by an information processing device. Microscope objective 6 and field lens 8 provide the necessary optical magnification, allowing the modulation signal to be captured by detector 9 without the need for a resolving grating. Reflector 7 is coated with a visible light reflective film, allowing X-rays to pass through directly, thus separating the visible light imaging path from the transmitted X-rays, reducing stray light interference, and simultaneously bending the optical path to compress the overall system volume.

[0084] After removing sample 4, a background exposure image without sample 4 is obtained. By comparing the changes in the modulation signal, the attenuation of X-ray intensity generated by the object causes a change in the fringe amplitude, reflecting absorption contrast information; X-ray refraction causes a phase shift in the fringes, reflecting phase contrast information; and small-angle scattering causes a change in fringe contrast, reflecting dark-field contrast information. Therefore, by solving the fringe image using methods such as phase stepping, multimodal information after object separation can be obtained. Additionally, an image-spinning system can be added to obtain an upright image, conforming to human visual perception.

[0085] Furthermore, it should be noted that the shapes and names of the parts and components described in the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this patent concept are included within the protection scope of this patent. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the structure of this invention or exceed the scope defined in these claims, they should all fall within the protection scope of this invention.

Claims

1. A single-phase grating X-ray microscopy imaging system based on two-stage amplification, characterized in that, Includes a geometric magnification system, an optical magnification system, and a detector; The geometric amplification system includes an X-ray tube, multiple capillaries, a phase grating, and a scintillator; An X-ray tube is provided at the inlet end of the multi-capillary tube. The multi-capillary tube is used to converge the X-ray beam emitted by the X-ray tube and decompose it into discrete point sources that meet the spatial coherence condition. Each discrete point source is incoherent with each other. The discrete point sources pass through the phase grating, and the X-ray beams are incoherent. The phase grating generates a diffraction self-imaging effect on the discrete point light source, forming a contrast-enhanced modulation signal, which is used to illuminate the sample under test. The scintillator converts the first modulation signal after passing through the sample into a fluorescence signal in the visible light band; The optical amplification system amplifies the fluorescence signal to obtain a fluorescence amplified signal, and separates the fluorescence amplified signal from the first modulation signal to obtain a single fluorescence amplified signal; The detector receives the single amplified fluorescence signal.

2. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 1, characterized in that, The magnification and imaging formula of a geometric magnification system is described as follows: in, , These represent the distance from the multi-capillary focal point to the sample and the distance from the sample to the scintillator, respectively. Indicates the divergence angle of the capillaries. This indicates the size of the resolvable feature in the image of the sample to be tested.

3. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 1, characterized in that, The formula for the Talbot distance between the discrete point source and the phase grating in the diffraction self-imaging effect is as follows: in, Indicates the wavelength of the incident light. The period of the grating is used to determine the distance from the phase grating to the scintillator.

4. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 1, characterized in that, The optical magnification system includes an objective lens module, a reflection module, and a field lens module; The objective lens module collects and amplifies the fluorescence signal generated by the scintillator to obtain a fluorescence amplification signal. The objective lens module is a 20x objective lens with a numerical aperture of 0.55 and a diffraction limit of 887nm~1552nm. The reflection module is equipped with a visible light band reflection film to separate the fluorescence amplification signal and the first modulation signal to obtain a single fluorescence amplification signal; The field lens module is used to reduce the light-transmitting aperture of the image and to compensate for the optical aberrations generated by the objective lens module. The formula for optical magnification obtained through the objective lens module and the field lens module is as follows: in, This refers to the working distance of the objective lens module. , These are the equivalent focal lengths of the objective lens module and the field lens module, respectively. This represents the distance between the objective lens module and the field lens module.

5. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 1, characterized in that, It also includes an information processing device, which is connected to the detector; The information processing device receives and analyzes at least the following information: The image includes an exposure image of the sample to be tested and a background exposure image without the sample to be tested. The exposure image containing the sample to be tested is obtained by superimposing the signal generated by the discrete point light source directly illuminating the sample to be tested and the image of the sample to be tested is obtained by superimposing the first modulation signal generated by the modulation signal illuminating the sample to be tested. The background exposure image is obtained under the same exposure conditions without the sample to be tested.

6. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 5, characterized in that, It also includes the following steps: At least three exposure images of the sample to be tested must be acquired; The corresponding pixels of the three exposure images of the sample to be tested are combined with the modulation signal generated by the phase grating to obtain multimodal information. The multimodal information is then decomposed to obtain absorption information, phase information and dark field information. Based on the three types of information obtained from multimodal information analysis and the principle of minimizing errors, the random errors caused by mechanical motors and the drift errors caused by grating jitter during the phase grating stepping process are optimized, thereby determining the optimal state of the phase grating.

7. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 5, characterized in that, It also includes the following steps: Flat-field correction is performed by centroid positioning and Gaussian beam fitting to adjust the position of the multi-capillary tubes, thereby adjusting the distribution of discrete point light sources.

8. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 5, characterized in that, It also includes the following steps: Acquire an image of the sample under test containing the first modulation signal and a background exposure image without the sample under test; The characteristic values ​​of the first modulation signal are calculated by using the phase stepping method to obtain the three contrast information of absorption, phase and dark field after separation, between the sample image to be tested and the background exposure image. The characteristic values ​​include amplitude, phase and contrast.

9. The single-phase grating X-ray microscopy imaging system based on two-stage amplification according to claim 1, characterized in that, The phase grating is a hexagonal grid grating; The modulation intensity of the hexagonal grid grating and the discrete point light source formed by each single tube in the multi-capillary tube corresponds to each other, so that the formed image is a diffractive conjugate image; the spacing between the hexagonal grid grating and the multi-capillary tube satisfies incoherent superposition enhancement.

Images